1 package org.opentrafficsim.core.definitions;
2
3 import java.lang.reflect.Field;
4 import java.util.Locale;
5
6 /**
7 * This class houses defaults instances for different types, such as GTU types and link types. The static fields should only be
8 * accessed in the setup of a simulation. The simulation itself should be fed the relevant types, and not assume any specific or
9 * more generic super type. Only in this way can simulations be run with entirely different type structures.
10 * <p>
11 * Copyright (c) 2022-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
12 * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
13 * </p>
14 * @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
15 * @author <a href="https://tudelft.nl/staff/p.knoppers-1">Peter Knoppers</a>
16 * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
17 */
18 public abstract class Defaults
19 {
20
21 /** Defaults for locale nl_NL. */
22 public static final DefaultsNl NL = new DefaultsNl();
23
24 /** Locale. */
25 private final Locale locale;
26
27 /**
28 * Constructor.
29 * @param locale Locale; locale.
30 */
31 protected Defaults(final Locale locale)
32 {
33 this.locale = locale;
34 }
35
36 /**
37 * Returns the locale.
38 * @return Locale; locale.
39 */
40 public Locale getLocale()
41 {
42 return this.locale;
43 }
44
45 /**
46 * Returns a default value of a type, indicated by its name. This should only be used by parsers. Simulations defined in
47 * code should access the relevant static fields directly for code maintainability.
48 * @param clazz Class<T>; class instance of type T.
49 * @param name String; name referring to a default through static field names, e.g. "NL.VEHICLE".
50 * @param <T> type of the value.
51 * @return T; returned default value, {@code null} if the default could not be found.
52 */
53 public static <T> T getByName(final Class<T> clazz, final String name)
54 {
55 return getByName(Defaults.class, clazz, name);
56 }
57
58 /**
59 * Returns a default value of a type, indicated by its name. This should only be used by parsers. Simulations defined in
60 * code should access the relevant static fields directly for code maintainability.
61 * @param defaultsClass Class<? extends Defaults>; defaults class.
62 * @param clazz Class<T>; class instance of type T.
63 * @param name String; name referring to a default through static field names, e.g. "NL.VEHICLE".
64 * @param <T> type of the value.
65 * @return T; returned default value, {@code null} if the default could not be found.
66 */
67 @SuppressWarnings("unchecked")
68 protected static <T> T getByName(final Class<? extends Defaults> defaultsClass, final Class<T> clazz, final String name)
69 {
70 try
71 {
72 String[] subNames = name.split("\\.");
73 Field field1 = defaultsClass.getDeclaredField(subNames[0]);
74 Object defaults = field1.get(defaultsClass);
75 Field field2 = defaults.getClass().getDeclaredField(subNames[1]);
76 return (T) field2.get(defaults.getClass());
77 }
78 catch (IllegalArgumentException | IllegalAccessException | NoSuchFieldException | SecurityException ex)
79 {
80 return null;
81 }
82 }
83
84 }